Modern production practices often involve printing an identification code on commercial products. These codes are easily observed on common products such as soda cans, cosmetics, pet food containers, etc. Some government regulatory agencies, such as the Food and Drug Administration, may require certain products to have such codes.
These codes often include information that is unique to the time and place at which the product is manufactured. For instance, many codes communicate a batch number associated with a product. Many codes go further and indicate the actual time and date of manufacture. Because some codes relate to unique manufacturing parameters (e.g., time and date), some codes cannot be pre-printed on a label for a product. Hence, a code is often printed on the label after the product is manufactured. Current code printing technology includes the use of ink jets, which spray ink onto the label.